Setting of a combination of parameter setting values (hereinafter referred to as observation conditions) which are setting values of parameters in operation of a scanning electron microscope (hereinafter referred to as the electron microscope) largely relies on experience. For this reason, when a novice user operating the electron microscope, the user has difficulty in knowing what kind of influence the electron microscope observation conditions have on a captured image. As a result, there is a problem that the novice user has a hard time improving his/her skills.
To counter such a problem, in techniques described in Patent Documents 1 and 2, image capturing is performed under two or more combinations of simple observation conditions prior to main image capturing. Then, two or more simple observation images thus obtained are displayed in a list form on a display unit (e preview). Subsequently, a user selects a desired simple observation image from the displayed simple observation images. Then, a computer sets the observation conditions for the selected simple observation image. Thereafter, the user makes necessary manual adjustment on the selected simple observation image, and then image capturing is performed. An image obtained as a result of the image capturing is displayed on the display unit.